Received: by 2002:a25:1985:0:0:0:0:0 with SMTP id 127csp661788ybz; Fri, 17 Apr 2020 07:52:57 -0700 (PDT) X-Google-Smtp-Source: APiQypI7EATjDwvY1WupBF/kZZlMvfJOXaKNfXEi1b0jJ7gGxwyOajzyrU3ZI7n9sp0XnFBk1Aea X-Received: by 2002:aa7:d60a:: with SMTP id c10mr3475188edr.66.1587135177336; Fri, 17 Apr 2020 07:52:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1587135177; cv=none; d=google.com; s=arc-20160816; b=uZGBOQK5u9JJdOer0T0qUuHlIDdo10FNkC4c0UMzXj649QRBxvon9bdWNf+7fEi99R nW00o4aWTGj02XCQZ7/K1gXR/aOgdL9s6csQ9MFq5/TeYicUm7jK0dzte0BPwMMKIRS4 EQCTT8OYlauvE5GFBEEsYgj7Vw+2fluowU1leaqd72iicR0/xmOsPsLDXslHTTCvq/gA hceWDeHdOpObhzWavHd5kiB54ANtOP14J0zpa5UnZZDhipgwEuK2gQWW8oQa99YzCoz+ ssx3RHoszfXVq4+pTGICVa6cPiaNLCMUwESaomjUu6aKk5H/UoK3EyPD35RpNkeLnJaU VinQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:to:references:in-reply-to:message-id:date :subject:cc:from; bh=rTIzfyHBG86KqZn8tr7Dk4igSP6RDjKe/Omw+tRj790=; b=pJPUa/lQ587owkdcF5q+pL+PInlJKXZlcdaoT0bUH1JxE01AUIjrrVFR9Wb8jtmN05 ypXchpSVGxTjJTf/maDKXkMjoHh8Gx3E/HKuBBc/FhOz08ZWS2D4Wv16A2hKQAxTqBVq D9P5GjsndCU21ifSlCnD6WtFavW8tC/Lq3KNLrLSYwysp4jhlbdTghSyqQ7Tv9USayrn 1saxaTkL7vc9DZZBlt7yZEg6Cy4lREWMmYJit8LA4vDXN7yjOfNikf1lt9NrTcnmVT0U OGE4q6NDMK2xc6u4kgYpooUc8j3XdjBnQENfhnK1zg2xwE/tmE5o+adJUP8RtI4/4eS0 TEZw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=alibaba.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id m13si1968552eja.163.2020.04.17.07.52.32; Fri, 17 Apr 2020 07:52:57 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=alibaba.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728221AbgDQOuv (ORCPT + 99 others); Fri, 17 Apr 2020 10:50:51 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:57169 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727877AbgDQOuu (ORCPT ); Fri, 17 Apr 2020 10:50:50 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01358;MF=alex.shi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0TvqJzQo_1587135046; Received: from localhost(mailfrom:alex.shi@linux.alibaba.com fp:SMTPD_---0TvqJzQo_1587135046) by smtp.aliyun-inc.com(127.0.0.1); Fri, 17 Apr 2020 22:50:47 +0800 From: Alex Shi Cc: Alex Shi , Thomas Gleixner , Davidlohr Bueso , Ingo Molnar , Will Deacon , linux-kernel@vger.kernel.org Subject: [PATCH 2/2] locking/rtmutex: optimize rt_mutex_cmpxchgs Date: Fri, 17 Apr 2020 22:50:32 +0800 Message-Id: <1587135032-188866-2-git-send-email-alex.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1587135032-188866-1-git-send-email-alex.shi@linux.alibaba.com> References: <1587135032-188866-1-git-send-email-alex.shi@linux.alibaba.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Checking l->owner first to skip time cost cmpxchgs. Suggested-by: Davidlohr Bueso Signed-off-by: Alex Shi Cc: Thomas Gleixner Cc: Davidlohr Bueso Cc: Ingo Molnar Cc: Will Deacon Cc: linux-kernel@vger.kernel.org --- kernel/locking/rtmutex.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c index cfdd5b93264d..232727a4a220 100644 --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -141,8 +141,10 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) * set up. */ #ifndef CONFIG_DEBUG_RT_MUTEXES -# define rt_mutex_cmpxchg_acquire(l,c,n) (cmpxchg_acquire(&l->owner, c, n) == c) -# define rt_mutex_cmpxchg_release(l,c,n) (cmpxchg_release(&l->owner, c, n) == c) +# define rt_mutex_cmpxchg_acquire(l, c, n) \ + (l->owner == c && cmpxchg_acquire(&l->owner, c, n) == c) +# define rt_mutex_cmpxchg_release(l, c, n) \ + (l->owner == c && cmpxchg_release(&l->owner, c, n) == c) /* * Callers must hold the ->wait_lock -- which is the whole purpose as we force -- 1.8.3.1